bios flashing doesnt void warranty but it is risky procedure that if not done properly could make mb inoperation (repair is possible but is time spending or may be costly as well). it is quite simple proces and if you follow instructions you have to be real idiot to fuck it up. call those guys and ask them for time/cost. if experance guy do it shouldnt take more then 30-40 mins if they have compatable cpu. it is kind of strange that you have such problems since according to mb's cpu support list it should be able to run fx6100 straight out of the box (fx6100 support is stated from firts releace version of bios). did you reproted beep code you got to gigabyte support and what they did told you about its meaning. also check in google what beep code could mean.